After last week's column about Captchas – the little visual tests that websites deploy alongside password requests to prove that you're human – reader Jo Franks pointed out how maddening they are for blind people. When I raised this issue on the Cyberclinic blog, Thomas Reid mentioned that a Captcha at blogcarnival.com in effect stops blind bloggers from joining in with their project. This obviously isn't a deliberate ploy. But it's far from unique.

Captchas are a small part of a whole spectrum of accessibility problems. Blind users normally rely on screen-reading software packages that recite out loud any text and links that appear on the screen; while free screen-readers are available, it's only the more sophisticated ones – such as Jaws 9.0 – that are easy to use, and these cost more than £500. But even Jaws starts to trip up if web designers don't bother to follow accessibility guidelines.

A study in 2004 showed that 81 per cent of websites failed to meet the most basic criteria for assisting the visually impaired; an organisation called WebAIM has produced a list of just 16 guidelines. But despite this, they've seen little overall improvement over the past 10 years.

In the UK, a case is coming to light of a blind American Express customer, Richard Godfrey-McKay (inset), who used to access his account details using Jaws, but since Amex implemented changes last December he's been stripped of that ability. Jaws now handles his statements, and the RNIB is supporting him with a possible action under the Disability Discrimination Act. While a number of unsuccessful cases have been brought against inaccessible sites in the past, the fact that Amex has actually withdrawn his facility – albeit unwittingly – may give this one more weight and, hopefully, strike a small blow for the visually impaired.

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